1. Technical Field
The present invention relates to a semiconductor laser device having a support member and a semiconductor laser element.
2. Discussion of the Related Art
Application of high current to a semiconductor laser element may cause catastrophic optical damage (COD). COD is an irreversible phenomenon in which ng of the end surfaces occurs due to an excessive light output greater than a predetermined value, leading to destruction of the semiconductor laser element, which results in termination of lasing.
Meanwhile, there has been known a semiconductor laser element in which an “ohmic electrode” for supplying electric current to the active layer has a length in the resonator direction less than the length of the resonator (for example, see Patent Literature 1: JP H11-340573A). With this structure, a region where the electric current is not supplied can be formed in the vicinity of the end surfaces, and therefore prevention of OCD can be expected.
See Patent Literature 1: JP H11-340573A.
However, according to the study of the present inventors, although simply arranging the “ohmic electrode” with a length less than the length of the resonator can prevent COD, it also leads to a phenomenon in which the light output rapidly decreases before the onset of COD (hereinafter referred to as “rapid degradation of light output”). A rapid degradation of light output is, together with COD, a major problem to be solved in order to realize a high output with a semiconductor laser element. Note that the rapid degradation of light output is a reversible phenomenon which does not damage or destroy a laser element and is a different phenomenon than the COD in which destruction of the end surfaces occurs.